More than five years after he left Downing Street, Tony Blair was brought back into the Labour fold last night with the award of a role advising Ed Miliband's policy review.

The move – likely to delight and dismay party activists in equal measure – was announced at a fund-raising event ahead of the London Olympics.

The former Prime Minister, who was in office when London was awarded the games, is to advise on how best to "maximise the sporting and economic legacy of the Olympics". The move also reflects Mr Blair's role in setting up a sporting foundation.

Appearing in public together for the first time since Mr Miliband's election as Labour leader, the two men, who were accompanied by their wives, shared a stage at Arsenal's Emirates stadium.

The former Prime Minister has made no secret of his support for the elder Miliband, David, to inherit the Labour crown in 2010, but last night was effusive about Ed Miliband's leadership qualities.

Mr Blair said: "It's an honour to be here to support our party, whose values and principles I have always believed in and always will, and to support Ed, support his leadership, support his drive to make our party win."

The current Labour leader replied by praising the former Prime Minister's record on the NHS, schools and cutting crime – and helping bring the games to Britain.

The event was organised by Alastair Campbell, Mr Blair's former director of communications, and Lady McDonagh, the former general secretary – both key figures in the New Labour project. Guests included Lord Prescott, Mr Blair's deputy for 13 years, and Sir Alex Ferguson, the Manchester United manager.

There is a determination around Mr Miliband, who was always more associated with Gordon Brown, to bring some key figures in the Blair era back from the cold, not least because they have practical experience of running successful general election campaigns. He has already appointed Jon Cruddas, a former Downing Street aide when Mr Blair was in office, to head the policy review.

For his part, Mr Blair has told friends he is keen to re-engage with domestic politics after spending much of his time on foreign affairs and building up his business interests.

Some Labour figures will be less keen to see him back – a significant minority of delegates cheered last year when Mr Miliband told the Labour conference that he was not Tony Blair.